Fastener strip with discrete magnetically attractable area, and method and apparatus of making same

ABSTRACT

The present invention provides a fastener strip having magnetic powders which are not located across a whole volume of a strip but are incorporated in each discrete distinct area of the strip. The fastener strip has a base plate and many hook pieces which rise from a fastening surface of the base plate. Further, the fastener strip has a magnetic body in a row which rises from the surface of the base plate as well as is located below a substantially center line of the fastener strip. The magnetic powders are incorporated in the magnetic body and a part of the base plate located below the magnetic body, and the magnetic powders are not dispersed across the whole area of the base plate. A method of manufacturing such a strip is also described here.

BACKGROUND

[0001] 1. Field of the Invention

[0002] This invention is in the area of touch fastening devices, specifically a fastener strip with magnetic bodies that are incorporated into discrete, individually distinct areas of the strip—rather than being distributed generally throughout the volume of the strip. A process for manufacturing such a strip is also described.

[0003] 2. Description of the Related Art

[0004] For example, a seat for a vehicle or the like is configured by attaching a superficial skin member on a surface of a cushion body. In this case, in order to satisfy a condition such that a seating posture is maintained and a person who is sitting on the seat is not tired even he or she is sitting for a long time on the basis of human factor engineering, a structure having a caved form is employed. In a sheet having such a caved form, in order to prevent the superficial skin member from floating from the cushion body at the caved form portion, as shown in FIG. 34, a foam molded article that a fastener strip 1 is fastened to the caved form portion is used as the cushion body and the fastener strip which is provided integrally on the cushion body and the fastener strip attached on a rear surface of the superficial skin member are adhesively engaged so as to prevent the floating of the superficial skin member.

[0005]FIG. 9 shows a production example of a cushion body, on which a fastener strip is provided on a surface of a foam molded article in an integrated manner. As shown in FIG. 9, a cushion body as a foam molded article, on which the fastener strip is provided in an integrated manner, is manufactured in such a manner that a fastening element surface of the fastener strip is mounted in a desired mold, abutting against a surface of the mold, a foam resin material is injected in the present mold and the foam resin material is foamed.

[0006] As a method of fixing the fastener strip on the surface of the mold, conventionally, a method is known such that a magnetic body is provided on a fastener strip side so as to fix the fastener strip by this magnetic body and a magnet disposed in the mold. The magnetically attractable components, namely, magnetic materials, have taken various forms, including metal staples, steel strips or shims, wire, porous metal webs or woven screens, and magnetic powders.

[0007] Then, as a constitution such that a magnetic body is disposed on the side of the fastener strip, for example, a constitution that a soft magnetic tape is provided on a film to prevent a foam resin from invading the fastening element surface upon foam-molding (Japanese Patent Application Laid-Open No. 4-109904), a constitution that a thin steel strip is clipped between a fastener strip and a lining (U.S. Pat. No. 4,673,542), a constitution that many magnetically attractable members are disposed adjacent to the edges of the opposite sides of a base plate of a fastener strip (U.S. Pat. No. 5,654,070), a constitution that a base plate of a fastener strip includes a magnetic deactivate substance which acts on a magnetic attractant (U.S. Pat. No. 5,725,928), a constitution that a porous magnetic web is embedded in a base plate of a fastener strip (U.S. Pat. No. 5,945,193) and the like are known.

[0008] As a magnetic body, which is used in this case, a constitution that a magnetic body is provided substantially all over a surface of a fastener strip in order to improve absorption power of a magnet in the mold (Japanese Patent Application Laid-Open No. 4-109904, U.S. Pat. No. 4,673,542, U.S. Pat. No. 5,725,928 and U.S. Pat. No. 5,945,193) or a constitution that many magnetically attractable members are disposed adjacent to the edges of the opposite sides of a base plate of a fastener strip (U.S. Pat. No. 5,654,070) is employed.

[0009] U.S. Pat. No. 5,500,268, for example, discloses magnetic powders which are incorporated into a foam seal also used to prevent fouling of the fastening elements during molding. U.S. Pat. Nos. 4,563,380; 4,710,414; and 4,784,890 describe the use of magnetic powders which are mixed into the adhesive used to attach together various elements of the fastener strip, such as an anchor layer or a backing layer. U.S. Pat. No. 5,540,970 discloses a fastener strip having magnetic powders embedded in an encasement which surrounds the hooks and thus prevents fouling; this encasement is then removed after the completion of the molding process. Additionally, U.S. Pat. No. 5,945,193 describes a porous metal web or woven screen which is embedded into the back of the fastener base plate, or into a backing or substrate layer attached to the base plate.

[0010] Further, U.S. Pat. No. 5,725,928 and 5,932,311 describe respectively a touch fastener, and a process of making the same, wherein the magnetic powders are incorporated into the entire hook and base layer, or into an entire substrate layer that is coextruded with the hook and base layer. This is accomplished by premixing ferromagnetic material into the resin stream feeding the entire extruder. U.S. Pat. No. 5,766,723 similarly discusses a fastener assembly wherein magnetic powders are incorporated into the entire hook and base layer, or into an entire backing layer which is later attached to the hook and base layer.

[0011] The prior art of the previous paragraph has a major disadvantage, however, in that the magnetic powders are mixed into the resin that forms the entire hook and base layer of the fastener strip, and/or the entire substrate layer if a substrate layer is used. Consequently, the magnetic powders are present throughout the entire volume of the base and/or substrate, rather than being present in only those areas where magnetic attraction is desired. This process is wasteful, because it uses more magnetic powders than might otherwise be needed. To the extent that magnetic powders in the resin can affect other properties of the fastener strip, it can also degrade performance.

[0012] A conventional fastener strip has mainly put emphasis on strengthening of the magnetic force, so that, if the fastener strip was merely mounted on a mold, the fastener strip was attracted and fixed on that position. Therefore, it was difficult to position the fastener strip. As a result, it was needed to position the fastener strip by hand one by one. Therefore, the working property to mount the fastener strip was not good and it took a long time for the mounting operation, so that it was requested to improve this demerit.

[0013] Thus it can be seen that a fastener strip having magnetic powders incorporated into the fastener strip only in discrete, targeted areas, and a manufacturing process for such a strip, would have significant advantages over the prior art. Accordingly, several objects and advantages of the invention are:

[0014] The location of the magnetic bodies can be precisely targeted within the base plate, within any members unitarily molded with the base plate, or within a substrate layer—the bodies need not be distributed across the extent of the fastener strip. As just one example, magnetic powders can be incorporated only into those portions of the base plate that underlie foam or other types of side seals, such that the magnetic force acts only on the sides of the strip. As another example, magnetic powders or long magnetic bodies can be incorporated only along the longitudinal center of the strip, which makes it easier to align the strip in the mold.

[0015] Generally, when the fastener strip having a narrow and long magnetic body is mounted in a magnetic field, which is generated from a magnet, the opposite ends in a longitudinal direction of the fastener strip are directed to the opposite poles of the magnet by the magnetism, so that a phenomenon that the opposite ends are identical with the directions of the opposite poles of the magnet occurs. By using this phenomenon, it is possible to easily position the fastener strip in a metal mold.

[0016] The process of the invention makes it faster and easier to purge resin containing magnetic powders from the extruder and other equipment. It is thus easier to cycle between extruding strips with magnetic powders and those without, using the same equipment, because the entire extruder does not have to be cleaned of magnetic powders. Instead, only that portion or portions through which magnetic powders have traveled must be cleaned. The line or channel which introduces the magnetic powders can even be turned off or on if desired. It is thereby possible to increase flexibility and reduce cycle times in the manufacturing process.

[0017] Incorporating magnetic powders or magnetic bodies only where needed lowers the cost of the fastener strip, by reducing waste and cutting equipment cleanup time.

[0018] To the extent that magnetic powders in the resin can adversely affect other properties of the fastener strip, the invention allows one to limit those effects to specifically defined areas.

[0019] Further objects and advantages of the invention will become apparent from a consideration of the drawings and ensuing description.

SUMMARY

[0020] The invention is a fastener strip with magnetic powders that are contained into discrete, individually distinct areas of the strip—rather than being distributed generally throughout the volume of the strip. A process for manufacturing such a strip is also described.

[0021] The basic constitution of the present invention is a fastening device, comprising:

[0022] (a) a base plate, and

[0023] (b) at least one fastening element carried on said base plate, and

[0024] (c) magnetic bodies arranged within a discrete area of said base plate, or within a discrete area comprising at least one integrally molded member carried on said base plate, whereby said fastening device can be magnetically secured to an object.

[0025] The magnetic body is not located on a whole area of the base plate but it is located within a discrete area which is a certain area of the base plate, so that the unnecessary use of the magnetic material is prevented as well as it is possible to make good use of attracting force by the magnetism to the fullest.

[0026] It is preferable that the magnetic body is located in the discrete area of the base plate along its longitudinal direction. Further, it is more preferable that the magnetic body is located in the discrete area of the base plate along a substantially longitudinal center thereof or the magnetic body is located in the discrete area of the base plate along a longitudinal side thereof, since it is easy to give a direction to the fastener strip upon positioning it on the mold.

[0027] Further, it is preferable that the magnetic body has a narrow shape which is elongated in the longitudinal direction of the base plate and, by a magnet, which is located on a predetermined position of the mold, the magnetic body has sufficient magnetism to bring the longitudinal opposite ends of the fastener strip into line with the directions of the opposite poles of this magnet.

[0028] Generally, if a narrow and long magnetic body is located in a magnetic field generated by a magnet, the magnetic body is magnetized by this magnetic field. Further, on the longitudinal opposite ends of the magnetized magnetic body, a plus magnetic pole and a negative magnetic pole are generated, respectively. In this case, when the magnetic flux density of the magnet is defined as H, the magnetic poles at the opposite ends of this magnetic body have the same strength and its strength is defined as m, the force of F=mH acts on the opposite ends of this magnetic body, respectively. By this force, the moving force acts on this magnetic body to direct it to the directions of the opposite magnetic poles of the magnet, so that this magnetic body is directed to the directions of the opposite magnetic poles of the magnet. Further, the magnetism of this magnetic body is attracted to the vicinity of a center of the opposite magnetic poles of this magnet.

[0029] In other words, if a fastener strip having a narrow and long magnetic body is mounted in a magnetic field, which is generated by a magnet, as described above, the opposite ends in a longitudinal direction of the fastener strip are directed to the opposite poles of the magnet by the magnetism, so that a phenomenon that the longitudinal opposite ends become identical with the directions of the opposite poles of the magnet occurs.

[0030] However, in the case that the long magnetic body is not narrow but wide, if the fastener strip having this wide magnetic body is located on a magnet with the longitudinal direction of this magnetic body inclined with respect to the opposite magnetic poles of the magnet, the magnetism of this magnetic body is attracted as the longitudinal direction of this magnetic body is inclined with respect to the opposite magnetic poles of the magnet. As a result, the longitudinal direction of the fastener strip is not directed to the direction of the opposite magnetic poles of the magnet. Although the force the same as the above described force also acts on a long and wide magnetic body, the volume of the movement of the long and wide magnetic body is smaller than that according to the magnetism of the narrow magnetic body. Therefore, it is not perceived that the above described force acts on the wide magnetic body as the magnetism sufficient to direct this wide magnetic body to the directions of the opposite magnetic poles of the magnet.

[0031] According to the present invention, the above described phenomenon generated by the long and narrow magnetic body and the magnet is applied to the fastener strip. Only by providing continuous narrow magnetic body along the longitudinal direction of the fastener strip base plate and mounting this fastener strip in the vicinity of a predetermined mounting position on the mold, it is possible to use the above phenomenon and position and fix the fastener strip on the desired position, even if this fastener strip is mounted without taking care of a positional relation between the longitudinal direction of the fastener strip base plate and the positions of the opposite magnetic poles of the magnet provided on a position where the fastener strip is mounted.

[0032] The width of the narrow magnetic body according to the present invention is capable of being changed by the size of the fastener strip provided with the narrow magnetic bodies, and the strength of the magnetic field of the magnet located in the mold. As long as the force, which acts on this magnetic body by the strength of the magnetic pole of the opposite sides of the magnetic body generated by this magnet and the magnetic flux density of this magnet, can be set to a volume sufficient to bring the opposite ends in the longitudinal direction of the fastener strip to the directions of the opposite poles of this magnet, it is possible to set an arbitrary width of the fastener strip. Alternatively, a magnetic body having a narrow shape elongated in the longitudinal direction of the fastener strip base plate may be formed in a shape that is continues in this longitudinal direction. Alternatively, the magnetic body may be formed in a shape that is discontinuous in this longitudinal direction. Both of the magnetic body in the shape that is continuous in this longitudinal direction and the magnetic body in the shape that is discontinuous in this longitudinal direction have functions as the magnetic body which effects the above described phenomenon.

[0033] Particularly, if the magnetic body is located centrally in width direction of the base plate or on its side end portion of the base plate along the longitudinal direction, it is possible to act the attraction force by the magnetic body and the magnet at a center of the fastener strip, so that it becomes possible to more strongly move the opposite ends in the longitudinal direction in the center in width direction of the fastener strip to the directions of the opposite poles of this magnet in addition to the above described effect.

[0034] It is preferable that the magnetic body is configured by at least one row of synthetic resin protrusion in which magnetic powders are mixed, and a surface of said protrusion is covered with a synthetic resin material which is the same as that of the base plate. With this feature, even when the resin used for the magnetic body and the resin used for the fastener strip have poor affinity, it is possible to avoid the exfoliation of the protrusion and the body of the fastener strip.

[0035] The foregoing magnetic body may be located on the base plate itself, however, this magnetic body may be formed as at least one row of synthetic resin protrusion including a magnetic material formed on the surface of the base plate. In this case, the magnetic material to be included in the synthetic resin protrusion may be a magnetic powders to be mixed in the synthetic resin or to be added to the synthetic resin, or it may be a magnetic metal wire, a magnetic tape or a long magnetic material such as a textile fabric woven from the synthetic resin mixed with a metal fiber and magnetic powders, and a non-woven fabric.

[0036] Alternatively, the synthetic resin protrusion may be formed to be continuous in the longitudinal direction of the base plate, however, it may form valley portions along the longitudinal direction of the base plate at even intervals. Thus, if the valley portions with even intervals are formed along the longitudinal direction of the base plate, the protrusion is easily bent at the valley portions, so that it becomes possible to make the fastener strip flexible.

[0037] In the case that the magnetic material is made of the magnetic powders, the magnetic powders such as iron, cobalt, nicker and the like is preferable. The magnetic material may be produced by molding with the synthetic resin material mixed with the magnetic powder upon producing the protrusion, applying a coating compound having the magnetic powder to a top of the magnetic material after molding the protrusion or laminating a resin film including the magnetic powder on the protrusion.

[0038] Alternatively, in the case that the magnetic material is made of a long magnetic material, it is possible to elongate the long magnetic body along the protrusions. In this case, particularly, the long magnetic material is elongated to communicate through the interiors of the protrusions so that portions of the long magnetic material are exposed at the valley portions. According to such a structure, it becomes easy to integrate the protrusions made of the synthetic resin with the long magnetic material, of which physical property is different from that of the synthetic resin, as well as it is possible to make the fastener strip flexible by the valley portions formed on the protrusions.

[0039] Alternatively, it is possible to fix the long magnetic material on the top of the protrusions. According to this structure of the magnetic body, when the fastener strip is mounted on the mold, the magnet disposed on the mold and the long magnetic material are closely located. Therefore, it is possible to obtain a certain and strong magnetism attraction force.

[0040] The foregoing magnetic body is capable of being composed of a plurality of fastening elements, which includes the magnetic material and whose base portions are connected each other. In the magnetic body according to such a structure, it is not required to form a cavity for the protrusion separately. A plurality of fastening elements, which includes the magnetic and located in a line in the longitudinal direction, functions as a long magnetic body upon mounting a fastener strip on the mold. Further, after the fastener strip is integrally formed on a surface of a foam molded article, a plurality of fastening elements originally functions as a fastening element.

[0041] The above described protrusions and the fastening element line, which functions as the magnetic body, are made of a thermoplastic resin to be molded on the base plate in an integral manner. As the thermoplastic resin, polyester, polyamide, polyolefin, polyvinyl chloride, polyurethane, polyolefin-elastomer, polyester-elastomer, polyamide-elastomer, polyisoprene and a synthetic resin such as a resin composition including other thermoplastic polymers may be considered.

[0042] The fastener strip provided with the above described structure is effectively manufactured by a manufacturing method and a manufacturing apparatus according to the present invention to be described below.

[0043] That is, a manufacturing method of a fastener strip comprises the steps of (a) arranging a magnetic powdery material and (b) incorporating the magnetic powdery material into a discrete area of a base layer of the touch fastening device or incorporating the magnetic powdery material into a discrete area provided with at least one member which is formed in an integral manner to be carried on the base layer of the touch fastening device. Further, the touch fastening device is capable of being magnetically fixed on an object.

[0044] It is preferable that the step for incorporating the magnetic powdery material preferably includes a step to extrude the plastic resin through an extruder and introduce the magnetic powdery material through a different flow channel in the extruder. The foregoing different flow channel has an outlet, which is located on a substantially center of a front surface of the extruder. Then, the mixture of the plastic resin and the magnetic powdery material is extruded to the base material of the fastener strip and the protrusions thereof through the different flow channel in the extruder.

[0045] Further, the procedure to incorporate the magnetic powdery material includes a step to extrude the plastic resin through the extruder toward a die wheel adjacent to the extruder, and to extrude the magnetic body through a different line. A magnetic body molding cavity is preferably located on a substantially center of a periphery of the die wheel.

[0046] A preferable manufacturing apparatus to manufacture the above described fastener strip comprises a magnetic body molding portion having a first extruding die having an extruding opening for extruding a synthetic resin, in which the magnetic powders are mixed and is in a molten state, and a first die wheel which is rotated around a horizontal axis and opposed to the extruding opening and has a magnetic body molding cavity formed along a peripheral surface in its rotational direction, and a fastener strip molding portion having a second extruding die having an extruding opening for extruding a synthetic resin in a molten state, a second die wheel which is rotated around a horizontal axis and opposed to the extruding opening and has a fastener strip molding cavity formed along a peripheral surface in its rotational direction, and a magnetic body guiding portion which is mounted upstream of a rotational direction of the second die wheel with respect to this second extruding die to guide the magnetic body molded article molded in the magnetic body molding portion to a predetermined position in the fastener strip molding cavity. The foregoing magnetic body molding cavity includes concave portions for protrusion having a narrow shape which are continuous in a peripheral direction or which are intermittently located. The foregoing fastener strip molding cavity includes concave portions for fastening element which are located at a predetermined pitch in a peripheral direction, and concave portions for accommodating a magnetic body molded article molded in the magnetic body molding portion.

[0047] Namely, a pair of manufacturing apparatuses (a magnetic body molding portion and a fastener strip molding portion) comprise an extruding die having an extruding opening for extruding a synthetic resin in a molten state, and a die wheel having a molding cavity which is opposed to this extruding opening and is formed along the rotation around a horizontal axis and a peripheral surface in this rotational direction. Further, one of the manufacturing apparatuses (a magnetic body molding portion) manufactures the magnetic body molded article and the other manufacturing apparatus (a fastener strip molding portion) manufactures the fastener strip molded article in which this magnetic molded article is formed in an integral manner.

[0048] The magnetic body molding portion comprises a first extruding die having an extruding opening to extrude a synthetic resin material in which the magnetic powders are mixed and which is in a molten state, and a first die wheel having a magnetic body molding cavity which is rotated around a horizontal axis opposing to this extruding opening and is formed along a peripheral surface in this rotational direction. And the fastener strip molding portion comprises a second extruding die having an extruding opening to extrude a synthetic resin material in a molten state, a second die wheel which is rotated around a horizontal axis and opposed to this extruding opening and has a fastener strip molding cavity formed along a peripheral surface in this rotational direction, and a magnetic body guiding portion mounted upstream in a rotational direction of a second die wheel with respect to the second extruding die to guide the magnetic body molded article molded in the magnetic body molding portion to a predetermined position in the fastener strip molding cavity.

[0049] In the first die wheel, a magnetic body molding cavity including concave portions for a protrusion having a narrow shape which are continuous in a peripheral direction or which are intermittently provided, is formed. And in the second die wheel, the fastener strip molding cavity including concave portions for fastening element provided at a predetermined pitch in a peripheral direction, and concave portions for accommodating a magnetic body molded article molded in the magnetic body molding portion, is formed.

[0050] Between the extruding opening and the die wheel, a clearance is defined. With this clearance portion, the protrusions formed in the concave portions for protrusion intermittently located are molded continuously.

[0051] By using a fastener strip manufacturing apparatus provided with such a constitution, the synthetic resin material, in which the magnetic powders are mixed and which is in a molten state, is extruded from the first extruding opening and the synthetic resin materials are continuously filled in the magnetic body molding cavity as the first die wheel is rotated. After that, the magnetic body molded article is stripped off from the peripheral surface of the first die wheel. In the same way, the synthetic resin material in the molten state is extruded from the second extruding opening and these synthetic resin materials are continuously filled in the fastener strip molding cavity as the second die wheel is rotated. After that, via the magnetic body guiding portion, the magnetic body molded article is continuously provided to the concave portions for accommodating in this fastener strip molding cavity. In this case, after melting and attaching the synthetic resin material and the magnetic body molded article to be integral, this fastener strip molded article including the magnetic body having fastening elements and a narrow shape is stripped off from the second die wheel to manufacture the fastener strip.

[0052] In other words, by filling the synthetic resin material, in which the magnetic powders are mixed and which is in the molten state, in the magnetic body molding cavity, a magnetic body molded article as a protrusion of the magnetic body is manufactured and these magnetic body molded articles are continuously provided in the fastener strip molding cavity, in which the synthetic resin materials are continuously provided, via the magnetic body guiding portion, so that the fastener strip having the magnetic body is manufactured.

[0053] The magnetic body molded article molded in the first die wheel is winded by a reel or the like, and then, as rewinding the magnetic body molded article from this reel or the like, this magnetic body molded article is provided to the second die wheel. As a result, it is possible to continuously manufacture the fastener strip having the magnetic body.

[0054] Alternatively, a magnetic body molded article molded in the first die wheel may be provided to the second die wheel not via a rewinding reel or the like but via the magnetic body guiding portion so as to continuously manufacture the fastener strip having the magnetic body. In the case of interposing the rewinding reel or the like, a dancer roller may be provided between the rewinding reel and the second die wheel, and in the case that the rewinding reel or the like is not interposed, a dancer roller may be provided between the second die wheel and the material guiding opening, so that it is possible to prevent the slack of the magnetic body molded articles to be continuously manufactured and to adjust the tension thereof.

[0055] With respect to a cross section shape of the magnetic body guiding portion, any cross section shapes may be applicable if they are similar to the cross section of the magnetic body molded article and a round shape with which the magnetic body guiding portion is certainly guided to the concave portions for accommodating the magnetic body molded article within the fastener strip molding cavity.

[0056] As another example of the manufacturing apparatus of the fastener strip, a magnetic body molding portion is provided to have a magnetic material guiding portion mounted upstream in a rotational direction of a first die wheel with respect to this first extruding die to guide the long magnetic material to a predetermined position of the concave portions for protrusion in the magnetic body molding cavity. The synthetic resin material in the molten state is extruded from the first extruding die to be filled in the cavity for molding the magnetic body formed in the first die wheel. Meanwhile, the long magnetic body is separately guided via the magnetic material guiding portion to be introduced in the cavity for molding the magnetic body. Then, the long magnetic body is integrated with the molten resin filled in the cavity for molding the magnetic body, so that a long magnetic body is formed. As same as the above described method, in the case of this long magnetic body also, the magnetic molded article is continuously provided to the concave portions for accommodating the magnetic body molded article within the fastener strip molding cavity via the magnetic body guiding portion, so that the fastener strip including the magnetic body having the fastening element and the narrow shape is molded.

[0057] The above described magnetic material guiding portion may be also formed on the first extruding die. When the magnetic material guiding portion to guide the long magnetic material is formed on the first extruding die, a guiding front end of this magnetic material guiding portion may be located in the vicinity of the concave portions for the protrusion of the magnetic body molding cavity. Therefore, it is possible to more certainly guide the long magnetic material to a predetermined position.

[0058] The above described fastener strip manufacturing apparatus is provided with a pair of manufacturing machines configured by the extruding die and the die wheel (magnetic body forming portion and a fastener strip forming portion). However, there is a fastener strip manufacturing apparatus configured by a set of the extruding die and the die wheel also.

[0059] In other words, this fastener strip manufacturing apparatus is provided with an extruding die having a pair of extruding openings to extrude the synthetic resin materials in the molten state separately and a die wheel which rotates around a horizontal axis and is opposed to these extruding openings and has a magnetic body molding cavity and a fastener strip molding cavity formed along the peripheral surface of this rotational direction. The foregoing cavities for molding include concave portions for protrusion having a narrow shape, which is continuous in a peripheral direction or which is intermittently located, as the magnetic body molding cavity and include concave portion for fastening element, which are located at a predetermined pitch in a peripheral direction, the a fastener strip molding cavity. The foregoing extruding die is provided with the pair of extruding openings at an upper position and a lower position along the rotational direction of the die wheel. The foregoing extruding opening at the upper position has a shape so as to regionally extrude the synthetic resin material in the molten state, in which the magnetic powders are mixed, to the magnetic body molding cavity and the extruding opening at the lower position has a shape so as to extrude the synthetic resin material in the molten state to the fastener strip molding cavity.

[0060] In other words, on the die wheel, the magnetic body molding cavity and the fastener strip molding cavity are formed on the same peripheral surface. It is characteristic that a molding surface including the concave portions for protrusion having a narrow shape which are continuous to a peripheral direction or which are intermittently located, as the magnetic body molding cavity as well as a molding surface including concave portions for fastening element located at a predetermined pitch in a peripheral direction, as the fastener strip molding cavity are formed on the cavities for molding.

[0061] Further, on the extruding die, a pair of extruding openings are formed on the upper and the lower positions along the rotational direction of the die wheel. In order to extrude the synthetic resin material in the molten state, in which the magnetic powders are mixed, to the magnetic body molding cavity from the extruding opening at the upper position, the extruding opening at the upper position has a shape for extruding the synthetic resin regionally so as to continuously fill the molten synthetic resin locally to the magnetic body molding cavity therefrom. On the other hand, the extruding opening at the lower position has a shape for extruding the synthetic resin in the molten state to the fastener strip molding cavity. By using this fastener strip manufacturing apparatus, it is possible to manufacture a fastener strip having the magnetic body by one step.

[0062] By using this fastener strip manufacturing apparatus, the synthetic resin material in the molten state, in which the magnetic powders are mixed, is extruded from the extruding opening at the upper position and the die wheel is rotated, so that this synthetic resin is continuously filled in the magnetic body molding cavity. Meanwhile, the synthetic resin material in the molten state is extruded from the extruding opening at the lower position to be continuously filled in the fastener strip molding cavity, which is formed in this die wheel. By peeling off the obtained fastener strip molded article including the magnetic body of a narrow shape and fastening elements from this die wheel, it is possible to continuously manufacture the fastener strip having the magnetic body as a final product by one step.

[0063] Alternatively, according to the above described fastener strip manufacturing apparatus, in place of using the synthetic resin material in a molten state, in which the magnetic powders are mixed, for manufacturing the magnetic body molded article, a guiding portion for a long magnetic material is provided so that the long magnetic material is continuously provided to a predetermined position within the magnetic body molding cavity via this guiding portion so as to continuously manufacture a magnetic body including the long magnetic material. The guiding portion of the long magnetic material is defined to be formed in the extruding die. In this case, if a magnetic material guiding portion to guide the long magnetic material is formed in the extruding die, it is possible to arrange a guiding front end portion of this magnetic material guiding portion in the vicinity of concave portions for protrusion of a magnetic body molding cavity.

[0064] Furthermore, the synthetic resin material in the molten state is extruded from the extruding opening of the extruding die, the die wheel is rotated to continuously fill this synthetic resin in the cavity for molding and a fastener strip molded article including the protrusions of the narrow shape and the fastening elements are continuously manufactured, then, it is also possible to form the magnetic body by performing laminate-processing of a layer including the magnetic powders to at least top surfaces of the protrusions or performing coating-processing including the magnetic powders to at least top surfaces of the protrusions.

[0065] The laminate-processing by a film or the like including the magnetic powders or the coating-processing by the resin and the coating material including the magnetic powders can be performed only on the top surfaces of the protrusions or on the surfaces of the protrusions along a longitudinal direction of the base plate. Further, it is possible to perform the above described processing across a whole area of the protrusions.

DESCRIPTION OF THE DRAWINGS

[0066]FIG. 1 is a top view of a fastener strip of the invention, showing a center row of magnetic bodies and the magnetic powders within them.

[0067]FIG. 2 is a cutaway end view of the fastener strip.

[0068]FIG. 3 is a top view of an alternative embodiment, wherein narrow magnetic bodies having magnetic powders within are located at opposing longitudinal sides of the fastener strip.

[0069]FIG. 4 is a top view of an alternative embodiment, in which a center row of a magnetic body is continued.

[0070]FIG. 5 is a perspective view of a fastener strip for illustrating an alternative embodiment according to the present invention.

[0071]FIG. 6 is a cross sectional view along a line VI-VI in FIG. 5.

[0072]FIG. 7 is a cross sectional view along a line VII-VII in FIG. 6.

[0073]FIG. 8 is a cross sectional view along a line VIII-VIII in FIG. 6.

[0074]FIG. 9 is a cross sectional view for illustrating a state in a mold of a foam sheet on which a fastener strip is mounted.

[0075]FIG. 10 is an essential part cross sectional view for illustrating a state such that a fastener strip is mounted on a lower portion of this mold.

[0076]FIG. 11 is an essential part cross sectional view for illustrating a state such that a foam resin material is injected in this mold.

[0077]FIG. 12 is a partial plan view for illustrating a state such that a foam resin material is entered between wall portions of a wall to prevent intrusion of the foam resin material.

[0078]FIG. 13 is a cross sectional view for illustrating a modification of the magnetic body.

[0079]FIG. 14 is a cross sectional view for illustrating another modification of the magnetic body.

[0080]FIG. 15 is a cross sectional view for illustrating a still another modification of the magnetic body.

[0081]FIG. 16 is a perspective view for illustrating another embodiment of a fastener strip.

[0082]FIG. 17 is a cross sectional view for illustrating a modification of the magnetic body.

[0083]FIG. 18 is a cross sectional view for illustrating a modification of the magnetic body.

[0084]FIG. 19 is a cross sectional view along a line XIX-XIX in FIG. 18.

[0085]FIG. 20 is a cross sectional view for illustrating still another modification of the magnetic body.

[0086]FIG. 21 is a cross sectional view along a line XXI-XXI in FIG. 20.

[0087]FIG. 22 is a cross sectional view for illustrating a still another modification of the magnet body.

[0088]FIG. 23 is a side view of the fastener strip extrusion process, showing particularly a supplementary particle supply and supplementary particle nozzle.

[0089]FIG. 24 is a front view of an extruder and a supplementary particle supply, illustrating outlets of the primary and supplementary particle nozzles.

[0090]FIG. 25 is a further side view illustrating a fastener strip extrusion process; in this view, an extruder and fastener strip have been cut away to show the discrete area having magnetic powders.

[0091]FIG. 26 is a front view of a die wheel, illustrating a hook forming cavities as well as a block forming cavity into which the magnetic powders are introduced.

[0092]FIG. 27 is a side view partially in cross section of another process embodiment, wherein the magnetic powders are introduced proximate to the block forming cavity in the die wheel.

[0093]FIG. 28 is a cutaway end view of an example fastener strip produced by another process embodiment of FIG. 27, wherein the magnetic powders are only within the center blocks, and not the base plate underlying the center blocks.

[0094]FIGS. 29A and 29B are cross sectional views for illustrating an arrangement of an extruding die, a material guiding opening and a die wheel.

[0095]FIG. 30 is a partial cross sectional view for illustrating a magnetic body molding cavity and a fastener strip molding cavity.

[0096]FIGS. 31A and 31B are views, in which a guiding portion of a metal wire as a long magnetic material is provided.

[0097]FIG. 32A is a cross sectional view for illustrating an arrangement of an extruding die of which a vertical pair of extruding openings are provided, a die wheel and a material guiding opening.

[0098]FIG. 32B is a partial front view illustrating an extruding opening of the extruding die.

[0099]FIG. 33 is a view, in which a guiding portion of a metal wire as a long magnetic material is provided.

[0100]FIG. 34 is a perspective view of a cushion body having a fastener strip fixed thereon in an integral manner.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0101] A list of reference numerals, which are used in the drawings, is as follows.

[0102]10: fastener strip

[0103]11: flat base plate

[0104]12: fastening element (hook piece)

[0105]13: magnetic body

[0106]13 a: protrusion

[0107]13 b: valley portion

[0108]13 c: base material portion

[0109]14: magnetic powder

[0110]15: wall

[0111]16: wall to protect intrusion of molding material

[0112]16 a: wall portion

[0113]17: foam resin material

[0114]18: laminate layer

[0115]19: coating film

[0116]20: metal wire

[0117]21: magnetic band material

[0118]22: long magnetic material

[0119]30: mold

[0120]30 b: lower portion of mold

[0121]31: magnet

[0122]35: extruder

[0123]36: die wheel

[0124]36 b: magnetic body molding cavity

[0125]37: supplementary particle reservoir

[0126]37 a: supplementary particle channel

[0127]37 b: supplementary particle nozzle

[0128]40: first extruding die

[0129]40 a: extruding opening

[0130]40 a-1: extruding nozzle portion

[0131]40 a-2: concave portion

[0132]41: second extruding die

[0133]41 a-1: extruding nozzle portion

[0134]41 a-2: concave portion

[0135]45: first die wheel

[0136]45 a: concave portion for protrusion

[0137]46 a: fastener strip molding cavity (concave portion)

[0138]46 b: concave portion for accommodating magnetic body

[0139]47, 48: magnetic body guiding portion

[0140]FIGS. 1 and 2 schematically show a top view of a cutaway end view of a primary embodiment according to the present invention. A fastener strip 10 having an engagement surface of this flat base plate 11 and a fastening element 12 configured by many hook pieces which rise from the base plate 11 further has a magnet body 13 in a row which rises from a surface of the base plate 11 and is located substantially below a center line of the fastener strip 10. The magnet body 13 is configured by many magnetic protrusions 13 a made of a synthetic resin material, in which magnetic powders 14 are mixed. The foregoing magnetic powders 14 are also mixed in a material portion 13 c of the base plate 11 below these protrusions 13 a and the magnetic powders 14 are not dispersed across a whole of the base plate 11. Accordingly, the magnetic body 13 comprises a continuous body in which valley portions 13 b are formed between the protrusions 13 a.

[0141]FIGS. 3 and 4 schematically illustrate another embodiment according to the present invention. FIG. 3 is a top view of the fastener strip 10. Each row of the magnetic body 13 has the magnetic powders 14, which are incorporated in a plurality of protrusions 13 a and it is located at opposing longitudinal sides of the fastener strip 10. FIG. 4 is a top view of the fastener strip 10 having continuous protruding magnetic body 13, which rises from a surface of the base plate 11 and is located substantially below a center line of the fastener strip 10. In FIGS. 3 and 4, other portions are same as the main embodiment according to the present invention.

[0142]FIGS. 5 through 8 specifically illustrate another typical embodiment according to the present invention. As shown in these drawings, the fastener strip 10 according to the present invention is provided with many fastening elements 12 on a surface of the flat base plate 11 except the opposite edge portions thereof. On the opposite edge portions thereof, walls 16 to prevent intrusion of molding material configured by many wall portions 16 a located on one line along a longitudinal direction are disposed, respectively. The protrusions 13 a of the magnetic body 13 are located at even intervals in a line on a center in a longitudinal direction of the base plate 11 and the valley portions 13 b are formed therebetween. It is possible to manufacture the wall 16 to prevent intrusion of the molding material, the base plate 11, the fastening element 12 and the protrusion 13 a from a thermoplastic resin by integral molding.

[0143] As shown in FIGS. 5 and 6, the protrusion 13 b has the base material portion 13 c on its base plate and it has a form of one continuous body by the base material portion 13 c. The base material portion 13 c and the protrusion 13 a can be manufactured by molding integrally from a thermoplastic resin in which magnetic powders are mixed. Further, as shown in FIGS. 5 and 6, it is possible to form the wall 16 to prevent intrusion of the molding material comprising the plurality of wall portions 16 a on the opposite edges of the fastener strip 10.

[0144] As shown in FIGS. 11 and 12, this wall portion 16 a protects a foam resin material 17 from intruding among the fastening elements 12 of the fastener strip 10 upon foam molding. Also, the wall portion 16 a allows itself to make a portion of the foam resin material 17 intrude among the fastening elements 12 of the fastener strip 10 through the gaps between the adjoining wall portions 16 a (see FIG. 8) and the wall portions 16 a are fixed by the intruded foam resin material 17 and the foam resin material 17 on the outside of the wall portions 16 a.

[0145] As shown in FIGS. 5 and 6, in the case that two rows of the wall 16 to prevent intrusion of the molding material are provided on each of the opposite edges of the fastener strip 10, if each pair of rows of the wall portions 16 a are located to be staggered each other as shown in FIGS. 5 and 8, it is possible to strengthen a sealing function in order to prevent the intrusion of the foam resin material. In other words, the foam resin material 17 intruded from the gap between the outside wall portions 16 a, strikes against the inside wall portions 16 a to be come round to the rear surface of the outside wall portions 16 a, so that the flow of the foam resin material 17 is changed. In order to prevent the intrusion of the foam resin material 17, it is necessary that the height of the protrusion 13 a is not more than the height of the wall portion 16 a. In the case that the wall 16 to prevent intrusion of the molding material comprises a continuous wall, the height of the protrusion 13 a is also required to be not more than the height of the wall portion 16 a.

[0146] According to the present invention, this wall 16 to prevent intrusion of the molding material is not always required and if such a wall 16 to prevent the intrusion of the molding material is not provided, the effects of the present invention can be realized. Alternatively, in place of the wall portions 16 a, a wall to prevent the intrusion of a molding resin may be provided along each of the opposite edges of the fastener strip 10.

[0147]FIGS. 9 through 12 illustrate an example of a mold upon molding the above described fastener strip 10 on the foam molded article in an integral manner and its molding mechanism. As shown in FIGS. 9 and 10, the magnetic body 13 is magnetically attracted by a magnet 31 provided on the mold 30, so as to position and fix the fastener strip 10 in the mold 30. When the magnetic body 13 is mounted above the magnet 31, a force acts on the magnetic body 13 by the strength of the magnetic poles on the opposite ends of the magnetic body generated by a magnetic field of the magnet 31, and the density of the magnetic flux, so that a force is effected so as to bring the opposing longitudinal edges of the fastener strip 10 having the magnetic body 13 into line with a direction of the opposing magnetic poles. According to the present embodiment, it is important that the magnetic body 13 has a narrow shape elongated in a longitudinal direction of the base plate 11 of the fastener strip 10, namely, the magnetic body 13 is so shaped that the magnetic body 13 is capable of bringing the opposing longitudinal edges of the fastener strip 10 into line with a direction of the opposing magnetic poles.

[0148] If the fastener strip 10 is mounted within the mold 30 as shown in FIG. 9, the fastener strip 10 is fixed on a lower portion 30 b of the mold 30, being magnetically attracted as facing to the direction of the opposite magnetic poles by the effect of the protrusions 13 a of the magnetic body 13 and the magnet 31 provided on the lower portion 30 b of the mold, as shown in FIG. 10. In other words, if the magnet 31 provided in the mold 30 is set in a desired direction necessary for mounting the fastener strip 10 in advance, it is possible to direct this fastener strip 10 to a desired direction merely by placing the fastener strip 10 according to the present invention on this magnet 31. As shown in FIG. 10, by this magnetically attraction, it is possible to close the wall portion 16 a and the surface of the lower portion 30 b of the mold 30.

[0149] FIGS. 13 to 22 show modifications of the protrusion 13 a as a magnetic body and illustrate a structure of the periphery of the protrusion.

[0150]FIG. 13 partially illustrates a structure such that the base material portion 13 c and the projection 13 a made of a thermoplastic resin mixed with the magnetic powders 14 are fixed on a surface of the base plate 11 in an integral manner. The projection 13 a and the base material portion 13 c as the magnetic body 13 may be manufactured by fixing it on the base plate 11 after it is separately molded with other component part of the fastener strip 10. Alternatively, the projection 13 a and the base material portion 13 c as the magnetic body 13 may be continuously manufactured by superimposing other component parts of the fastener strip 10 on the magnetic body 10 as manufacturing this magnetic body 10.

[0151]FIG. 14 illustrates a part of a structure such that a layer including the magnetic powders 14 at a front end of the protrusion 13 a is laminate-processed in the fastener strip 10 on which the protrusion 13 a is molded in an integral manner. The thickness of the laminate layer 18 is needed to be a thickness such that the magnetic body 13 realizes the effect of the present invention.

[0152]FIG. 15 illustrates a structure such that a coating film 19 including the magnetic powders 14 is formed in place of the laminate layer 18 made of the synthetic resin including the magnetic powders 14.

[0153] In FIGS. 14 and 15, the magnetic laminate layers 18 or the magnetic coating films 19 may be formed only at the front ends of the protrusions 13 a. Alternatively, the magnetic laminate layers 18 or the magnetic coating films 19 may be formed over all surfaces of the protrusions 13 a. Further, the magnetic laminate layers 18 or the magnetic coating films 19 may be at only top surface along a longitudinal direction of the magnetic body 13.

[0154]FIG. 16 illustrates an example of a protrusion 13 a having a continuous shape without a valley portion, as a magnetic body 13. The magnetic body may be formed by using a thermoplastic resin material, in which the magnetic powders are mixed. Alternatively, as shown in FIGS. 14 and 15, the laminate layer may be formed or the magnetic coating film may be formed.

[0155]FIG. 17 illustrates a structure such that two rows of the protrusions 13 a as the magnetic body 13 are formed. In this case, the two rows of the protrusions 13 a are connected with the base material portion 13 c in the bottom. However, the two rows of the protrusions 13 a may be structured to be separate and not connected. As the magnetic material to be formed to be the protrusions 13 a, a thermoplastic resin, in which the magnetic powders 14 are mixed, may be used to form the magnetic body in an integrated manner. Further, the laminate layer including the magnetic powders 14 may be formed or the magnetic coating film may be formed. In this case, the above described various methods to form the magnetic body 13 can be appropriately employed.

[0156]FIG. 18 illustrates a structure such that, in place of the protrusion 13 a, some of the fastening elements 12 are formed by the magnetic material so as to form the magnetic body 13. In this case, as shown in FIG. 19, the base plates of the two rows of the fastening elements 12 formed by the magnetic material are connected so as not to disperse the magnetic force and the two rows of the fastening elements 12 are structured as one piece of the magnetic body 13 having a long and narrow shape as a whole. Alternatively, the base plates of the fastening elements 12 are not needed to be connected. Further, the number of these fastening element rows may be two or more than two.

[0157] The fastening element row, in which the magnetic powders 14 are mixed, has a function as the magnetic body 13 as well as an inherent engagement function of the fastening element 12.

[0158]FIG. 20 illustrates a structure such that the metal wire 20 as the long magnetic material constitutes the magnetic body 13 located along the protrusions 13 a, in the case that the magnetic body 13 is configured by the continuous protrusion 13 a. According to this example, the metal wire 20 having a circular cross section is located within the protrusion 13 a. However, in place of this, the metal wire 20 having a rectangular cross section or the metal wire 20 having other various form cross sections may be employed. Alternatively, the metal wire 20 may be mounted on a front end of the protrusion 13 a. Alternatively, as shown in FIG. 21, a structure such that the metal wire 20 is exposed in the valley portion 13 b formed between the protrusions 13 a may be employed.

[0159]FIG. 22 illustrates an example such that the long magnetic material is structured by the magnetic band material 21 located along the top surfaces of the protrusions 13 a, which is composed of, for example, a magnetic tape or a woven and knitted fabric which is woven and knitted by the synthetic resin fiber in which the metal fiber and the metal powder are mixed or a non woven fabric formed by the metal fiber. Alternatively, the magnetic band material 21 also may be located within the protrusions 13 a.

[0160] The magnetic band material 21 is adhesively fixed on the top surfaces of the protrusions 13 a or the synthetic resin material in a molten state is intruded between the gaps of the fibers to come round to the peripheries of the fibers upon molding the protrusions 13 a, so that the magnetic band material 21 is fixed. Alternatively, in place of the magnetic band material 21, a magnetic rope material formed by the foregoing fibers may be available.

[0161] FIGS. 23 to 26 schematically show the process by which fastener strip 10 is formed, and the equipment used therein. It should be noted here that the basic process of manufacturing a resin-based fastener strip via an extruder and die/forming wheel combination is known in the art; accordingly, the entire process has not been illustrated, but rather that portion of the process relevant to the invention.

[0162]FIG. 23 is a side view of the fastener strip extrusion process of the invention, wherein an extruder 35 is positioned adjacent to a die wheel 36. The die wheel 36 is cylindrical in shape, and has a plurality of hook-shaped cavities 36 a for fastening element and a magnetic body molding cavity 36 b, both located around its outer circumference as further detailed in FIG. 26. The extruder 35 is elongated in shape, extends across the cylindrical breadth of the die wheel 36, and contains a series of primary channels (not shown) through which resin 24 flows. A supplemental particle reservoir 37 is located on the top surface of the extruder 35. A supplemental particle channel 37 a (indicated by hidden lines) connects the supplemental particle reservoir 37 to a supplemental particle nozzle 37 b located on the face of the extruder 35 proximate to the die wheel 36.

[0163]FIG. 24 is a front view of the die-wheel-proximate face of the extruder 35. A plurality of primary nozzles 35 a extend across the extruding face of the extruder 16, and the supplementary particle nozzle 37 b is located generally in the center of the extruding face of the extruder 35. Further, FIG. 23 illustrates the “piggyback” position of the supplemental particle reservoir 37 over the extruder 35, and the center position of the supplementary particle channel 37 a within the extruder 35.

[0164] As shown in FIG. 23, the molten resin 24 is urged through the primary channels in the extruder 35 and consequently through the primary nozzles 35 a. The die wheel 36 rotates counterclockwise in this view, and as the resin 24 is extruded through the primary nozzles 35 a, the die wheel 36 acts with the lower front face of the extruder 35 to continuously form the fastener strip 10 having the base plate 11 and the hooks 12. Simultaneously, and as shown in the FIG. 25 cutaway view, a stream of the magnetically attractable resin material 25 containing magnetic powders 14 is urged from the supplementary particle reservoir 37 through the supplementary particle channel 37 a and the supplementary particle nozzle 37 b. The supplementary particle nozzle 37 b is aligned with the magnetic body molding cavity 36 b, such that the magnetically attractable resin 25 emerges from the supplementary particle nozzle 37 b, forms a discrete portion of the base plate 11, and is also formed into the blocks 13 on the base plate 11 by the magnetic body molding cavity 36 b. It can be seen that while the magnetically attractable resin 25 becomes an integral part of the extruded fastener strip 10, the magnetic powders 14 remain in a discrete area, and are not dispersed generally throughout the base plate 11. The fastener strip 10, having a discrete, targeted magnetically attractable area, is thereby continuously formed and withdrawn from the bottom periphery of the die wheel 36.

[0165]FIG. 27 is a side view of an alternative process embodiment partially in cross section, wherein the magnetic powders 14 are introduced directly into the block forming cavity 23, instead of passing through the extruder 35 as in the main embodiment. In this embodiment, the supplementary particle reservoir 37 is placed in any suitable location, and the stream of the magnetically attractable resin 25 is conveyed through the line 26 to the die wheel 36, in the area of the magnetic body molding cavity 36 b. As in the main process embodiment, it can be seen that while the magnetically attractable resin 25 becomes an integral part of the extruded fastener strip 10, the magnetic powders 14 remain in a discrete area, and are not dispersed generally throughout the base plate 11. Other process steps are the same as in the main embodiment.

[0166]FIG. 28 is a cutaway end view of an example fastener strip produced by the alternative process embodiment of FIG. 24. In this example, the magnetic powders are only within the center protrusion 13 a, and not within the base plate underlying the center blocks. However, it can be appreciated that by varying the flow rate of the magnetically attractable resin 25 in relation to the flow rate of the resin 24, the rotational speed of the die wheel 36, and the proximity of the outlet of line 26 to the magnetic body molding cavity 36 b, one can control the extent of magnetic powders 14 in the base plate 11 and in any member molded with and carried on the base plate 11. Thus, while FIG. 28 shows an example with the magnetic powders only within the center protrusion 13 b, and not within the underlying base plate 11, certainly the alternative process embodiment of FIG. 27 can also produce a fastener strip like that shown in FIG. 2, wherein the magnetic powders 14 are within both the center protrusions 13 b and the underlying base plate.

[0167] Conclusions, Ramifications, and Scope:

[0168] Thus the reader will see that this invention provides a very effective way to incorporate magnetic powders into specifically targeted areas of a fastener strip. While the above descriptions contain many specificities, these shall not be construed as limitations on the scope of the invention, but rather as exemplifications of embodiments thereof. Many other variations are possible. Examples of just a few of the possible variations follow:

[0169] The supplemental particle reservoir does not have to be located above the extruder in a “piggyback” fashion as in the main embodiment. It may be located in any suitable location, and a line or tube used to convey the magnetic powders to the supplementary particle channel.

[0170] There can be many different ways to urge the magnetic powders, or a resin containing such particles, from a reservoir through a channel or line to a nozzle or line outlet. Such techniques are known in the art, and include conveyance by way of air or hydraulic pressure, gravity, or other means.

[0171] The stream of magnetic powders can travel through its own dedicated channel in the extruder, as in the main embodiment, or can “join” one of the other channels in the extruder, upstream from the nozzle.

[0172] The magnetic body can be incorporated into a discrete area of a substrate which is formed with the base plate or formed separately. In this case, the substrate would effectively be a part of the base plate.

[0173] In addition to the above-mentioned, the magnetic powders can include, but are not limited to, all ferromagnetic materials, including iron powder, various forms of iron oxide, iron stearate, various organo-iron compounds, rare-earth metals and rare-earth metal compounds, or any other magnetically attractable material.

[0174] In addition, it should be understood that the magnetic powders can themselves be magnetically attractive—that is, be magnets themselves. This would allow the fastener strip to be secured to metal or other magnetically attractable objects which are not magnets themselves,.

[0175] The magnetic powders can be premixed into a resin, or they can be “loose” particles which are conveyed down into a resin stream.

[0176] The shape of the discrete magnetically attractable magnetic body can be different than the protrusion, fastening element, and wall shown, and as just an example, square cubes can also be used. In addition, of course, magnetic powders can be incorporated into a discrete area of the base plate only. In this case, the discrete area of the base plate can be substantially flat, without having any members overlying it, or it can alternatively have members overlying it.

[0177] The fastening elements carried on the base plate, and/or incorporated with magnetic powders, can be different than the hook fasteners shown in the drawings—as just one example, they can be loop fastening elements instead. Indeed, other types of fastening or engaging elements—not just hooks or loops—can also be used.

[0178] The magnetic bodies can be incorporated into the discrete areas at any location on the fastener strip, not just the center location shown in the main embodiment and the side locations shown in FIG. 3. For example, the supplementary particle nozzle can be positioned on the face of the extruder adjacent to a hook forming cavity, so that magnetically attractable hook members are formed on the base plate of the fastener strip. A similar result can be obtained, in the alternative process embodiment, by positioning the outlet of the line proximate to a hook forming cavity.

[0179] Supplementary particle nozzles can be placed in multiple locations on the face of the extruder, and line outlets can be placed in multiple locations proximate to the die wheel—rather than having just one supplementary particle nozzle or one line outlet as in FIGS. 23, 24, 25, and 27. Indeed, the fastener strip shown in FIG. 3 results from such a multiple placement.

[0180] The magnetic powders can be introduced into the resin stream in a discrete area immediately above the resin as it emerges from the primary nozzles, rather than via the supplementary particle nozzle as in the FIG. 5 main embodiment or directly into the magnetic body molding cavity as in the FIG. 9 alternative embodiment.

[0181] A method of manufacturing a fastener strip manufacturing apparatus as well as the manufacturing apparatus thereof will be further specifically explained by describing other embodiments based on the above described various modifications with reference to the drawings below.

[0182]FIGS. 29A, 29B and 30 illustrate a fastener strip manufacturing apparatus and a method of manufacturing the fastener strip of the invention.

[0183]FIGS. 29A and 29B show that the fastener strip is manufactured by two steps. As shown in FIG. 29A, a first die wheel 45 is located opposing to an extruding opening 40 a of a first extruding die 40. The first die wheel 45 is rotated around a rotational axis in a vertical direction with respect to a paper surface in FIG. 19. A magnetic body molding cavity is formed on the rotation peripheral surface of the first die wheel 45. As the magnetic body molding cavity, concave portions 45 a for protrusion, having a narrow shape, and being intermittently located in a peripheral direction, are formed.

[0184] A clearance is defined between the first extruding die 40 and the first die wheel 45, and the base material portion 13 c of the magnetic body 13 as shown in FIG. 6 is molded by this clearance. Alternatively, the concave portions 45 a for protrusion may be molded, being continuous in the peripheral direction of the first die wheel 45.

[0185] In FIG. 29B, a second die wheel 46 is located opposing to an extruding opening 41 a of a second extruding die 41. A second die wheel 46 is rotated around a rotational axis perpendicular to the paper surface in FIG. 29B. A fastener strip molding cavity 46 a is formed on the rotation peripheral surface of the second die wheel 46. As a fastener strip molding cavity, as shown in FIG. 30, a fastener strip molding cavity 46 a including concave portions for fastening element located at a predetermined pitch in a peripheral direction and concave portion for molding a base plate, concave portions 46 b for accommodating a magnetic body, concave portions of a member which configure a fastener strip including other parts, for example, concave portions of a wall to protect the intrusion of a molding material and a wall portion or the like (not illustrated) are formed as necessary.

[0186] In FIG. 29A, the molten synthetic resin material 25 located within the first extruding die 40, in which the magnetic powders are mixed, is extruded from the extruding opening 40 a, so that the molten synthetic resin material 24 is continuously filled within the magnetic body molding cavity of the first die wheel 45 rotating around the horizontal axis. Then, the magnetic body 13 (the molded article) having the protrusion 13 a and the base material portion 13 c is peeled off from the first die wheel 45.

[0187] In FIG. 29B, the molten synthetic resin material 24 located within the second extruding die 41 is extruded from the extruding opening 41 a, so that the molten synthetic resin material 24 is continuously filled within the fastener strip molding cavity 46 a of the second die wheel 46 rotating around the horizontal axis. Then, the molded article 13 molded before, is continuously supplied to the concave portions 46 b for accommodating the magnetic body in the fastener strip molding cavity via the magnetic body guiding portion 47. The fastener strip molded article including the base plate 11, the fastening elements 12 and the protrusion 13 a is peeled off from the second die wheel 46 to manufacture the fastener strip 10. Further, the manufactured fastener strip 10 is cut by a desired length to be used.

[0188] According to an example shown in FIG. 30, a cross section shape of the concave portion 46 b for accommodating the magnetic body formed in the second die wheel 46 is larger that that of the magnetic body 13, which is separately molded, particularly, than the cross section shape of the protrusion 13 a thereof. Therefore, at least the surface of the protrusion 13 a is coated by the resin for molding 24 of the fastener strip 10. As a result, even when the resin used for the magnetic body 13 and the resin used for the fastener strip 10 have poor affinity, it is possible to avoid the exfoliation of the protrusion 13 a and the body of the fastener strip 10.

[0189] According to the example shown in FIGS. 29A and 29B, the molten synthetic resin material 25, in which the magnetic powders are mixed, is extruded from the extruding opening 40 a of the first extruding die 40. However, as shown in FIGS. 31A and 31B, it is also possible to manufacture the fastener strip 10 in such a manner that the synthetic resin material, in which the magnetic powders are not mixed, is extruded from the extruding opening 40 a, the long magnetic material 22 separately prepared is guided via a magnetic body guiding portion 48 to mold the magnetic mold article as a magnetic body 13 and this magnetic body 13 is supplied through the magnetic body guiding portion 47 located upstream side in the rotational direction of the second die wheel 46 shown in FIG. 29B.

[0190]FIG. 31A illustrates a structure such that the magnetic body guiding portion 48 is provided outside of the extruding die 40 and FIG. 31B illustrates an example such that the magnetic body guiding portion 48 is formed inside of the extruding die 40. Other component parts are the same as those in FIG. 29A.

[0191] An example shown in FIGS. 32A and 32B is different from the cases shown in FIGS. 28 through 31. According to the example in FIGS. 32A and 32B, the fastener strip 10 is manufactured by one step. Thus, according to this embodiment, solely the extruding die 41 is used, the fastener strip 10 having the magnetic body is manufactured.

[0192] According to the examples shown in the drawings, except that the extruding openings 40 a and 41 a are provided on the upper and lower positions of the extruding die 41, a positional relation between the extruding die 41 and the die wheel 46 is the same as the case shown in FIGS. 29A and 29B, so that the explanation is omitted herein and the same reference numerals are used. The two extruding openings 40 a and 41 a provided on the extruding die 41 are capable of extruding the different synthetic resins, respectively. As shown in FIG. 32B, at a front end of the extruding opening 40 a, an extruding nozzle portion 40 a-1 and a concave portion 40 a-2 are formed. This concave portion 40 a-2 is formed so that it is possible to continuously fill the molten synthetic resin, in which the magnetic powders are intensively mixed, into the narrow shaped concave portions for the protrusion formed for molding the magnetic body, which is continuous to a peripheral direction or is intermittently located, from the extruding opening 40 a. As a result, the synthetic resin extruded from the extruding nozzle portion 40 a-1 is regionally filled in the concave portions for the projection, so that it is possible to prevent the synthetic resin from being filled into the concave portion for the fastening element located adjacent thereto.

[0193] The extruding opening 41 a located at a lower position is placed in any location suitable for corresponding concave portions in association with the fastener strip molding cavity 46 a defined in the die wheel 46, for example, the concave portion for the projection, the concave portion for the fastening element and the like. Further, the extruding nozzle portion 41 a-1 and the concave portions 41 a-2 located at the periphery thereof are formed at a front end of the extruding opening 41 a. The synthetic resin material 25 extruded from the extruding nozzle portion 41 a-1 is expanded on the concave portions 41 a-2, so that it is possible to continuously fill the synthetic resin material 25 from a whole surface of the fastener strip molding cavity 46 b.

[0194] Then, the molten magnetic resin material 25, in which the magnetic powders are mixed, is extruded from the extruding opening 40 a to be continuously filled within the magnetic body molding cavity. Therefore, the magnetic body is manufactured. Simultaneously, the molten magnetic resin material 25 is extruded from the extruding opening 41 a to be continuously filled within the fastener strip molding cavity 46 a. By filling the synthetic resin material 24 from the extruding opening 41 a, it is possible to form the magnetic body 13 of the synthetic resin material 24 extruded from the extruding opening 40 a on the base plate 11 in an integral manner so as to be superposed on the base plate 11, as shown in FIG. 13. Alternatively, as shown in FIG. 6 and FIG. 17, it is also possible to continuously fill the synthetic resin material 24 in such a manner that the magnetic body 13 and the base plate 11 are connected in a strip width direction.

[0195] After filling the synthetic resin material 24, if the fastener strip molded article is peeled off from the die wheel, the continuous fastener strip is obtained. Further, it is possible to use this continuous fastener strip by cutting it into desired length.

[0196] As shown in FIG. 33, the synthetic resin material 24, in which the magnetic powders are not mixed, is extruded from the extruding opening 40 a to be filled in the fastener strip molding cavities 46 a and 46 b (in this case, the concave portion for molding the magnetic body and the concave portion for molding the fastener strip). By continuously supplying the long magnetic material 22 from the magnetic body guiding portion 48, the magnetic body portion in which the long magnetic material 22 is provided in the protrusion 13 a is formed. After that, by peeling off the fastener strip molded article from the die wheel, the fastener strip 10 is manufactured.

[0197] Additionally, according to a structure shown in FIG. 23, the fastener strip 10 is molded without providing the magnetic material guiding portion 22 and the magnetic material is laminate-processed or coating-processed at least on the top of the protrusion 13 a in the fastener strip molded article, which was molded, so as to form the magnetic body.

[0198] As a structure of the molding cavity, the concave portions for the protrusion may be formed at even intervals on a peripheral direction of the peripheral surface of the die wheel and along a direction of the rotational axis of the die wheel. It is possible to manufacture the fastener strip by using such molding cavity. In this case, it is necessary that the continuously molded fastener strip is cut between the adjacent protrusions to manufacture the fastener strip element. The above described magnetic member may be applied at least on the top surfaces of the protrusions after cutting the fastener strip or before cutting the fastener strip.

[0199] According to the examples shown in FIGS. 29A, 29B to 33, the apparatus and the manufacturing method of any fastener strip may be applied if it is within the range of a typical example and it is not deviated from the object of the present invention. Accordingly, a scope of the present invention should be decided not by the embodiments shown in the drawings but by the attached claims and the legal equivalent thereto. 

What is claimed is:
 1. A fastener strip comprising: (a) a base plate; (b) at least one fastening element to be carried on said base plate; and (c) a magnetic body which is incorporated within a discrete area of said base plate or within a discrete area comprising at least one integrally molded member carried on said base plate; wherein said fastener strip can be magnetically secured to an object.
 2. The fastener strip according to claim 1, wherein said magnetic body is incorporated within said discrete area of said base plate along a longitudinal dimension thereof.
 3. The fastener strip according to claim 2, wherein said magnetic body is incorporated within said discrete area of said base plate substantially along the longitudinal center thereof.
 4. The fastener strip according to claim 2, wherein said magnetic body is incorporated within said discrete area of said base plate along a longitudinal side thereof.
 5. The fastener strip according to claim 1, wherein said magnetic body has a narrow shape elongated in a longitudinal direction of said base plate, and has sufficient magnetism to bring the longitudinal opposite ends of said fastener strip into line with the directions of the opposite poles of said magnet by a magnet located on a predetermined position of a mold for a foam molded article.
 6. The fastener strip according to claim 5, wherein said magnetic body is configured by at least one row of synthetic resin protrusion in which magnetic powders are mixed, and a surface of said protrusion is covered with a synthetic resin material which is the same as that of the base plate.
 7. The fastener strip according to claim 5, wherein said magnetic body is included in said base plate.
 8. The fastener strip according to claim 5, wherein said magnetic body is configured by at least one row of synthetic resin protrusions including magnetic material formed on a surface of said base plate.
 9. The fastener strip according to claim 7 or 8, wherein said magnetic material is magnetic powders.
 10. The fastener strip according to claim 7 or 8, wherein said magnetic body is made of a long magnetic material.
 11. The fastener strip according to claim 8, wherein said protrusions are configured in such a manner that valley portions are formed with equal intervals along a longitudinal direction of said base plate.
 12. The fastener strip according to claim 11, wherein said long magnetic material is exposed on said valley portions of said protrusions.
 13. The fastener strip according to claim 8, wherein said long magnetic material is fixed on top surfaces of said protrusions.
 14. The fastener strip according to claim 8, wherein said protrusions include a plurality of fastening elements, which include magnetic materials and whose base plates are connected with each other.
 15. The fastener strip according to any one of claims 1 to 8, wherein said protrusions include thermoplastic resins and are formed on said base plate in an integral manner.
 16. A manufacturing method of a fastener strip comprising the steps of: (a) arranging a magnetic powdery material; and (b) incorporating said magnetic powdery material within a discrete area of a base layer of said fastener strip or incorporating said magnetic powdery material within a discrete area comprising at least one integrally molded member to be carried on said base layer of said fastener strip; wherein said fastener strip can be magnetically secured on an object.
 17. The method according to claim 16, wherein said step to incorporate said magnetic powdery material includes a step to extrude a plastic resin through an extruder and introduce said magnetic powdery material through a separate flow channel in said extruder.
 18. The method according to claim 17, wherein said separate flow channel has an outlet located substantially in the center of a front surface of said extruder.
 19. The method according to claim 15, wherein said introducing procedure includes a step to exclude a mixture of a plastic resin and said magnetic powdery material through said different flow channel in said extruder.
 20. The method according to claim 14, wherein said step to incorporate said magnetic powdery material includes a step to extrude the plastic resin through said extruder and extrude said magnetic powdery material through a separate line toward a die wheel adjacent to said extruder.
 21. The method according to claim 18, wherein said separate line has an outlet located in proximate to a molding cavity in said die wheel.
 22. The method according to claim 21, wherein said molding cavity is located on a substantially center on a peripheral surface of said die wheel.
 23. The method according to claim 20, wherein said introducing procedure includes a step to extrude the mixture of the plastic resin and said magnetic powdery material to said die wheel through said separate line.
 24. A fastener strip manufacturing apparatus comprising: a magnetic body molding portion having a first extruding die having an extruding opening to extrude a synthetic resin material in a molten state, in which magnetic powders are mixed, and a first die wheel which is rotated around a horizontal axis and opposed to said extruding opening and which has a magnetic body molding cavity formed along a peripheral surface in its rotational direction; and a fastener strip molding portion having a second extruding die having an extruding opening for extruding a synthetic resin in a molten state, a second die wheel which is rotated around a horizontal axis, opposing to said extruding opening and has a fastener strip molding cavity formed along a peripheral surface in its rotational direction, and a magnetic body guiding portion which is located upstream in a rotational direction of said second die wheel with respect to said second extruding die to guide a magnetic body molded article molded in said magnetic body molding portion to a predetermined position in said fastener strip molding cavity; wherein said magnetic body molding cavity includes concave portions for protrusion having a narrow shape which are continuous to a peripheral direction or which are intermittently located, and said fastener strip molding cavity includes concave portions for fastening element located at a predetermined pitch in a peripheral direction, and concave portions for accommodating a magnetic body molded article molded in said magnetic body molding portion.
 25. A manufacturing method of a fastener strip for using a fastener strip manufacturing apparatus according to claim 24, comprising the steps of: extruding a synthetic resin material in a molten state, in which magnetic powders are mixed, from the extruding opening of the first extruding die to continuously fill said synthetic resin material in said magnetic body molding cavity as rotating said first die wheel; peeling off the magnetic body molded article from a peripheral surface of said first die wheel; extruding the synthetic resin material in a molten state from the extruding opening of the second extruding die to continuously fill said synthetic resin material in said fastener strip molding cavity as rotating said second die wheel; continuously providing said magnetic body molded article to said concave portions for accommodating in said fastener strip molding cavity via said magnetic body guiding portion; melting and attaching said synthetic resin material and said magnetic body molded article to be integral; and peeling off the fastener strip molded article including a magnetic body having the fastening elements and a narrow shape from said second die wheel.
 26. A fastener strip manufacturing apparatus comprising: a magnetic body molding portion having a first extruding die having an extruding opening to extrude a synthetic resin material in a molten state, a first die wheel which is rotated around a horizontal axis and opposed to said extruding opening and has a magnetic body molding cavity formed along a peripheral surface in its rotational direction, and a magnetic body guiding portion which is located upstream side of the rotational direction of said first die wheel with respect to said first extruding die to guide a long magnetic body to a predetermined position of concave portions for a protrusion in said magnetic body molding cavity; and a fastener strip molding portion having a second extruding die having an extruding opening for extruding a synthetic resin in a molten state, a second die wheel which is rotated around a horizontal axis and opposed to said extruding opening and has a fastener strip molding cavity formed along a peripheral surface in its rotational direction, and a magnetic body guiding portion located upstream in a rotational direction of the second die wheel with respect to said second extruding die to guide a magnetic body molded article molded in said magnetic body molding portion to a predetermined position in said fastener strip molding cavity; wherein said magnetic body molding cavity includes concave portions for protrusion having a narrow shape which are continuous in a peripheral direction or which are intermittently located, and said fastener strip molding cavity includes concave portions for fastening elements located at a predetermined pitch in a peripheral direction, and concave portions for accommodating the magnetic body molded article molded in said magnetic body molding portion.
 27. The fastener strip manufacturing apparatus according to claim 26, wherein a long magnetic material guiding portion is formed in said first extruding die.
 28. A manufacturing method of a fastener strip for using a fastener strip manufacturing apparatus according to claim 26 or 27, comprising the steps of: extruding the synthetic resin material in a molten state from the extruding opening of the first extruding die to continuously fill said synthetic resin material in said magnetic body molding cavity and said fastener strip molding cavity as rotating said die wheel; continuously supplying the long magnetic material to a predetermined position of said concave portions for protrusion via said magnetic body guiding portion; connecting said synthetic resin material with said long magnetic material to be integral; peeling off the magnetic body molded article from the peripheral surface of said first die wheel; extruding the synthetic resin material in a molten state from the extruding opening of the second extruding die to continuously fill said synthetic resin material in said fastener strip molding cavity formed in said second die wheel; continuously supplying said magnetic body molded article to said concave portions for accommodating in said fastener strip molding cavity via said magnetic body guiding portion; melting and attaching said synthetic resin and said magnetic body molded article to be integral; and peeling off the fastener strip molded article including said fastening elements and said narrow shaped magnetic body from said second die wheel.
 29. A fastener strip manufacturing apparatus comprising: an extruding die having a pair of extruding openings to extrude a synthetic resin material in a molten state separately and a die wheel which is rotated around a horizontal axis and opposed to said extruding openings and has a magnetic body molding cavity and a fastener strip molding cavity formed along a peripheral surface in its rotational direction; wherein said magnetic body molding cavity includes concave portions for protrusion having a narrow shape which are continuous in a peripheral direction or which are intermittently located and said fastener strip molding cavity includes concave portions for fastening element located at a predetermined pitch in a peripheral direction; said pair of extruding openings are formed on the upper and lower positions of said extruding die along a rotational direction of said die wheel; said extruding opening on the upper position has a shape so as to regionally extrude the synthetic resin material in the molten state, in which magnetic powders are mixed, to said magnetic body molding cavity and said extruding opening on the lower position has a shape so as to regionally extrude the synthetic resin material in the molten state to said fastener strip molding cavity.
 30. A fastener strip manufacturing method for using a fastener strip manufacturing apparatus according to claim 29, comprising the steps of: extruding a synthetic resin material in the molten state, in which the magnetic powders are mixed, from said extruding opening located at the upper position to continuously fill said synthetic resin in said magnetic body molding cavity as rotating said die wheel; extruding the synthetic resin material in the molten state from said extruding opening located at the lower position to continuously fill said synthetic resin material in said fastener strip molding cavity as rotating said die wheel; and peeling off a fastener strip molded article including a magnet body having fastening elements and a narrow shape from said die wheel.
 31. A fastener strip manufacturing apparatus comprising: an extruding die having an extruding opening to extrude a synthetic resin material in a molten state, a die wheel which is rotated around a horizontal axis and opposed to said extruding opening and which has a magnetic body molding cavity and a fastener strip molding cavity formed along a peripheral surface in its rotational direction, and a magnetic body guiding portion located upstream side of the rotational direction of said die wheel with respect to said extruding die to guide a long magnetic body to a predetermined position in said magnetic body molding cavity; wherein said magnetic body molding cavity includes concave portions for protrusion having a narrow shape, which are continuous in a peripheral direction or which are intermittently located and said fastener strip molding cavity includes concave portions for fastening element, which are located at a predetermined pitch in a peripheral direction; said magnetic body guiding portion is formed in a shape so as to direct a long magnetic material to a predetermined position in said concave portions for the protrusion.
 32. The fastener strip manufacturing apparatus according to claim 31, wherein said magnetic body guiding portion is formed in said extruding die.
 33. A manufacturing method of a fastener strip for using a fastener strip manufacturing apparatus according to claim 31 or 32, comprising the steps of: extruding the synthetic resin material in the molten state from the extruding opening to continuously fill said synthetic resin material in said magnetic body molding cavity as rotating said die wheel; continuously supplying a long magnetic material to a predetermined position of said concave portions for protrusion via said magnetic body guiding portion; connecting said synthetic resin material with said long magnetic material to be integral; peeling off a fastener strip molded article including a magnetic body having said fastening elements and a narrow shape from said die wheel.
 34. A fastener strip manufacturing method comprising the steps of: preparing an extruding die having an extruding opening for extruding a synthetic resin material in a molten state; preparing a die wheel, which are rotated around a horizontal axis and opposed to said extruding openings and has a magnetic body molding cavity and a fastener strip molding cavity formed along a peripheral surface in its rotational direction; preparing said die wheel wherein said molding cavities include concave portions for protrusion having a narrow shape which are continuous in a peripheral direction or which are intermittently located for molding a magnetic body and concave portions for fastening elements located at a predetermined pitch in a peripheral direction for molding a fastener strip; extruding the synthetic resin material in the molten state from said extruding opening of said extruding die to continuously fill said synthetic resin material in said molding cavity as rotating said die wheel; peeling off a fastener strip molded article including said fastening elements and said narrow shaped protrusions from said die wheel; and performing laminate-processing of a layer including the magnetic powders or performing coating-processing of a layer including the magnetic powders on at least on the top surfaces of the protrusions.
 35. A fastener strip manufacturing method comprising the steps of: preparing an extruding die having an extruding opening for extruding a synthetic resin material in a molten state; preparing a die wheel which are rotated around a horizontal axis and opposed to said extruding openings and has a magnetic body molding cavity and a fastener strip molding cavity formed along a peripheral surface in its rotational direction; preparing said die wheel wherein said molding cavity includes concave portions for protrusion having a narrow shape which are located at even intervals in a peripheral direction of said die wheel as well as are continuous in a direction of a die wheel axis or which are intermittently located for molding a magnetic body and concave portions for fastening elements located at a predetermined pitch in a peripheral direction for molding a fastener strip; extruding the synthetic resin material in the molten state from said extruding opening of said extruding die to continuously fill said synthetic resin material in said molding cavity as rotating said die wheel; peeling off a fastener strip molded article including said fastening elements and said narrow shaped protrusions from said die wheel; performing laminate-processing of a layer including the magnetic powders or performing coating-processing of a layer including the magnetic powders at least on the top surfaces of the protrusions; and cutting said fastener strip molded article between the adjoining protrusions in said peripheral direction. 